Trait ByteSlice
pub trait ByteSlice: Sealed {
Show 76 methods
// Provided methods
fn as_bstr(&self) -> &BStr { ... }
fn as_bstr_mut(&mut self) -> &mut BStr { ... }
fn from_os_str(os_str: &OsStr) -> Option<&[u8]> { ... }
fn from_path(path: &Path) -> Option<&[u8]> { ... }
fn to_str(&self) -> Result<&str, Utf8Error> { ... }
unsafe fn to_str_unchecked(&self) -> &str { ... }
fn to_str_lossy(&self) -> Cow<'_, str> { ... }
fn to_str_lossy_into(&self, dest: &mut String) { ... }
fn to_os_str(&self) -> Result<&OsStr, Utf8Error> { ... }
fn to_os_str_lossy(&self) -> Cow<'_, OsStr> { ... }
fn to_path(&self) -> Result<&Path, Utf8Error> { ... }
fn to_path_lossy(&self) -> Cow<'_, Path> { ... }
fn repeatn(&self, n: usize) -> Vec<u8> ⓘ { ... }
fn contains_str<B>(&self, needle: B) -> bool
where B: AsRef<[u8]> { ... }
fn starts_with_str<B>(&self, prefix: B) -> bool
where B: AsRef<[u8]> { ... }
fn ends_with_str<B>(&self, suffix: B) -> bool
where B: AsRef<[u8]> { ... }
fn find<B>(&self, needle: B) -> Option<usize>
where B: AsRef<[u8]> { ... }
fn rfind<B>(&self, needle: B) -> Option<usize>
where B: AsRef<[u8]> { ... }
fn find_iter<'h, 'n, B>(&'h self, needle: &'n B) -> Find<'h, 'n>
where B: AsRef<[u8]> + ?Sized { ... }
fn rfind_iter<'h, 'n, B>(&'h self, needle: &'n B) -> FindReverse<'h, 'n>
where B: AsRef<[u8]> + ?Sized { ... }
fn find_byte(&self, byte: u8) -> Option<usize> { ... }
fn rfind_byte(&self, byte: u8) -> Option<usize> { ... }
fn find_char(&self, ch: char) -> Option<usize> { ... }
fn rfind_char(&self, ch: char) -> Option<usize> { ... }
fn find_byteset<B>(&self, byteset: B) -> Option<usize>
where B: AsRef<[u8]> { ... }
fn find_not_byteset<B>(&self, byteset: B) -> Option<usize>
where B: AsRef<[u8]> { ... }
fn rfind_byteset<B>(&self, byteset: B) -> Option<usize>
where B: AsRef<[u8]> { ... }
fn rfind_not_byteset<B>(&self, byteset: B) -> Option<usize>
where B: AsRef<[u8]> { ... }
fn fields(&self) -> Fields<'_> { ... }
fn fields_with<F>(&self, f: F) -> FieldsWith<'_, F>
where F: FnMut(char) -> bool { ... }
fn split_str<'h, 's, B>(&'h self, splitter: &'s B) -> Split<'h, 's>
where B: AsRef<[u8]> + ?Sized { ... }
fn rsplit_str<'h, 's, B>(&'h self, splitter: &'s B) -> SplitReverse<'h, 's>
where B: AsRef<[u8]> + ?Sized { ... }
fn split_once_str<'a, B>(
&'a self,
splitter: &B,
) -> Option<(&'a [u8], &'a [u8])>
where B: AsRef<[u8]> + ?Sized { ... }
fn rsplit_once_str<'a, B>(
&'a self,
splitter: &B,
) -> Option<(&'a [u8], &'a [u8])>
where B: AsRef<[u8]> + ?Sized { ... }
fn splitn_str<'h, 's, B>(
&'h self,
limit: usize,
splitter: &'s B,
) -> SplitN<'h, 's>
where B: AsRef<[u8]> + ?Sized { ... }
fn rsplitn_str<'h, 's, B>(
&'h self,
limit: usize,
splitter: &'s B,
) -> SplitNReverse<'h, 's>
where B: AsRef<[u8]> + ?Sized { ... }
fn replace<N, R>(&self, needle: N, replacement: R) -> Vec<u8> ⓘ
where N: AsRef<[u8]>,
R: AsRef<[u8]> { ... }
fn replacen<N, R>(&self, needle: N, replacement: R, limit: usize) -> Vec<u8> ⓘ
where N: AsRef<[u8]>,
R: AsRef<[u8]> { ... }
fn replace_into<N, R>(&self, needle: N, replacement: R, dest: &mut Vec<u8>)
where N: AsRef<[u8]>,
R: AsRef<[u8]> { ... }
fn replacen_into<N, R>(
&self,
needle: N,
replacement: R,
limit: usize,
dest: &mut Vec<u8>,
)
where N: AsRef<[u8]>,
R: AsRef<[u8]> { ... }
fn bytes(&self) -> Bytes<'_> { ... }
fn chars(&self) -> Chars<'_> { ... }
fn char_indices(&self) -> CharIndices<'_> { ... }
fn utf8_chunks(&self) -> Utf8Chunks<'_> { ... }
fn graphemes(&self) -> Graphemes<'_> { ... }
fn grapheme_indices(&self) -> GraphemeIndices<'_> { ... }
fn words(&self) -> Words<'_> { ... }
fn word_indices(&self) -> WordIndices<'_> { ... }
fn words_with_breaks(&self) -> WordsWithBreaks<'_> { ... }
fn words_with_break_indices(&self) -> WordsWithBreakIndices<'_> { ... }
fn sentences(&self) -> Sentences<'_> { ... }
fn sentence_indices(&self) -> SentenceIndices<'_> { ... }
fn lines(&self) -> Lines<'_> { ... }
fn lines_with_terminator(&self) -> LinesWithTerminator<'_> { ... }
fn trim(&self) -> &[u8] ⓘ { ... }
fn trim_start(&self) -> &[u8] ⓘ { ... }
fn trim_end(&self) -> &[u8] ⓘ { ... }
fn trim_with<F>(&self, trim: F) -> &[u8] ⓘ
where F: FnMut(char) -> bool { ... }
fn trim_start_with<F>(&self, trim: F) -> &[u8] ⓘ
where F: FnMut(char) -> bool { ... }
fn trim_end_with<F>(&self, trim: F) -> &[u8] ⓘ
where F: FnMut(char) -> bool { ... }
fn to_lowercase(&self) -> Vec<u8> ⓘ { ... }
fn to_lowercase_into(&self, buf: &mut Vec<u8>) { ... }
fn to_ascii_lowercase(&self) -> Vec<u8> ⓘ { ... }
fn make_ascii_lowercase(&mut self) { ... }
fn to_uppercase(&self) -> Vec<u8> ⓘ { ... }
fn to_uppercase_into(&self, buf: &mut Vec<u8>) { ... }
fn to_ascii_uppercase(&self) -> Vec<u8> ⓘ { ... }
fn make_ascii_uppercase(&mut self) { ... }
fn escape_bytes(&self) -> EscapeBytes<'_> { ... }
fn reverse_bytes(&mut self) { ... }
fn reverse_chars(&mut self) { ... }
fn reverse_graphemes(&mut self) { ... }
fn is_ascii(&self) -> bool { ... }
fn is_utf8(&self) -> bool { ... }
fn last_byte(&self) -> Option<u8> { ... }
fn find_non_ascii_byte(&self) -> Option<usize> { ... }
}
Expand description
A trait that extends &[u8]
with string oriented methods.
This trait is sealed and cannot be implemented outside of bstr
.
Provided Methods§
fn as_bstr(&self) -> &BStr
fn as_bstr(&self) -> &BStr
Return this byte slice as a &BStr
.
Use &BStr
is useful because of its fmt::Debug
representation
and various other trait implementations (such as PartialEq
and
PartialOrd
). In particular, the Debug
implementation for BStr
shows its bytes as a normal string. For invalid UTF-8, hex escape
sequences are used.
§Examples
Basic usage:
use bstr::ByteSlice;
println!("{:?}", b"foo\xFFbar".as_bstr());
fn as_bstr_mut(&mut self) -> &mut BStr
fn as_bstr_mut(&mut self) -> &mut BStr
Return this byte slice as a &mut BStr
.
Use &mut BStr
is useful because of its fmt::Debug
representation
and various other trait implementations (such as PartialEq
and
PartialOrd
). In particular, the Debug
implementation for BStr
shows its bytes as a normal string. For invalid UTF-8, hex escape
sequences are used.
§Examples
Basic usage:
use bstr::ByteSlice;
let mut bytes = *b"foo\xFFbar";
println!("{:?}", &mut bytes.as_bstr_mut());
fn from_os_str(os_str: &OsStr) -> Option<&[u8]>
fn from_os_str(os_str: &OsStr) -> Option<&[u8]>
Create an immutable byte string from an OS string slice.
When the underlying bytes of OS strings are accessible, then this
always succeeds and is zero cost. Otherwise, this returns None
if the
given OS string is not valid UTF-8. (For example, when the underlying
bytes are inaccessible on Windows, file paths are allowed to be a
sequence of arbitrary 16-bit integers. Not all such sequences can be
transcoded to valid UTF-8.)
§Examples
Basic usage:
use std::ffi::OsStr;
use bstr::{B, ByteSlice};
let os_str = OsStr::new("foo");
let bs = <[u8]>::from_os_str(os_str).expect("should be valid UTF-8");
assert_eq!(bs, B("foo"));
fn from_path(path: &Path) -> Option<&[u8]>
fn from_path(path: &Path) -> Option<&[u8]>
Create an immutable byte string from a file path.
When the underlying bytes of paths are accessible, then this always
succeeds and is zero cost. Otherwise, this returns None
if the given
path is not valid UTF-8. (For example, when the underlying bytes are
inaccessible on Windows, file paths are allowed to be a sequence of
arbitrary 16-bit integers. Not all such sequences can be transcoded to
valid UTF-8.)
§Examples
Basic usage:
use std::path::Path;
use bstr::{B, ByteSlice};
let path = Path::new("foo");
let bs = <[u8]>::from_path(path).expect("should be valid UTF-8");
assert_eq!(bs, B("foo"));
fn to_str(&self) -> Result<&str, Utf8Error>
fn to_str(&self) -> Result<&str, Utf8Error>
Safely convert this byte string into a &str
if it’s valid UTF-8.
If this byte string is not valid UTF-8, then an error is returned. The error returned indicates the first invalid byte found and the length of the error.
In cases where a lossy conversion to &str
is acceptable, then use one
of the to_str_lossy
or
to_str_lossy_into
methods.
§Examples
Basic usage:
use bstr::{B, ByteSlice, ByteVec};
let s = B("☃βツ").to_str()?;
assert_eq!("☃βツ", s);
let mut bstring = <Vec<u8>>::from("☃βツ");
bstring.push(b'\xFF');
let err = bstring.to_str().unwrap_err();
assert_eq!(8, err.valid_up_to());
unsafe fn to_str_unchecked(&self) -> &str
unsafe fn to_str_unchecked(&self) -> &str
Unsafely convert this byte string into a &str
, without checking for
valid UTF-8.
§Safety
Callers must ensure that this byte string is valid UTF-8 before
calling this method. Converting a byte string into a &str
that is
not valid UTF-8 is considered undefined behavior.
This routine is useful in performance sensitive contexts where the
UTF-8 validity of the byte string is already known and it is
undesirable to pay the cost of an additional UTF-8 validation check
that to_str
performs.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
// SAFETY: This is safe because string literals are guaranteed to be
// valid UTF-8 by the Rust compiler.
let s = unsafe { B("☃βツ").to_str_unchecked() };
assert_eq!("☃βツ", s);
fn to_str_lossy(&self) -> Cow<'_, str>
fn to_str_lossy(&self) -> Cow<'_, str>
Convert this byte string to a valid UTF-8 string by replacing invalid
UTF-8 bytes with the Unicode replacement codepoint (U+FFFD
).
If the byte string is already valid UTF-8, then no copying or allocation is performed and a borrrowed string slice is returned. If the byte string is not valid UTF-8, then an owned string buffer is returned with invalid bytes replaced by the replacement codepoint.
This method uses the “substitution of maximal subparts” (Unicode Standard, Chapter 3, Section 9) strategy for inserting the replacement codepoint. Specifically, a replacement codepoint is inserted whenever a byte is found that cannot possibly lead to a valid code unit sequence. If there were previous bytes that represented a prefix of a well-formed code unit sequence, then all of those bytes are substituted with a single replacement codepoint. The “substitution of maximal subparts” strategy is the same strategy used by W3C’s Encoding standard. For a more precise description of the maximal subpart strategy, see the Unicode Standard, Chapter 3, Section 9. See also Public Review Issue #121.
N.B. Rust’s standard library also appears to use the same strategy, but it does not appear to be an API guarantee.
§Examples
Basic usage:
use std::borrow::Cow;
use bstr::ByteSlice;
let mut bstring = <Vec<u8>>::from("☃βツ");
assert_eq!(Cow::Borrowed("☃βツ"), bstring.to_str_lossy());
// Add a byte that makes the sequence invalid.
bstring.push(b'\xFF');
assert_eq!(Cow::Borrowed("☃βツ\u{FFFD}"), bstring.to_str_lossy());
This demonstrates the “maximal subpart” substitution logic.
use bstr::{B, ByteSlice};
// \x61 is the ASCII codepoint for 'a'.
// \xF1\x80\x80 is a valid 3-byte code unit prefix.
// \xE1\x80 is a valid 2-byte code unit prefix.
// \xC2 is a valid 1-byte code unit prefix.
// \x62 is the ASCII codepoint for 'b'.
//
// In sum, each of the prefixes is replaced by a single replacement
// codepoint since none of the prefixes are properly completed. This
// is in contrast to other strategies that might insert a replacement
// codepoint for every single byte.
let bs = B(b"\x61\xF1\x80\x80\xE1\x80\xC2\x62");
assert_eq!("a\u{FFFD}\u{FFFD}\u{FFFD}b", bs.to_str_lossy());
fn to_str_lossy_into(&self, dest: &mut String)
fn to_str_lossy_into(&self, dest: &mut String)
Copy the contents of this byte string into the given owned string
buffer, while replacing invalid UTF-8 code unit sequences with the
Unicode replacement codepoint (U+FFFD
).
This method uses the same “substitution of maximal subparts” strategy
for inserting the replacement codepoint as the
to_str_lossy
method.
This routine is useful for amortizing allocation. However, unlike
to_str_lossy
, this routine will always copy the contents of this
byte string into the destination buffer, even if this byte string is
valid UTF-8.
§Examples
Basic usage:
use std::borrow::Cow;
use bstr::ByteSlice;
let mut bstring = <Vec<u8>>::from("☃βツ");
// Add a byte that makes the sequence invalid.
bstring.push(b'\xFF');
let mut dest = String::new();
bstring.to_str_lossy_into(&mut dest);
assert_eq!("☃βツ\u{FFFD}", dest);
fn to_os_str(&self) -> Result<&OsStr, Utf8Error>
fn to_os_str(&self) -> Result<&OsStr, Utf8Error>
Create an OS string slice from this byte string.
When OS strings can be constructed from arbitrary byte sequences, this
always succeeds and is zero cost. Otherwise, this returns a UTF-8
decoding error if this byte string is not valid UTF-8. (For example,
assuming the representation of OsStr
is opaque on Windows, file paths
are allowed to be a sequence of arbitrary 16-bit integers. There is
no obvious mapping from an arbitrary sequence of 8-bit integers to an
arbitrary sequence of 16-bit integers. If the representation of OsStr
is even opened up, then this will convert any sequence of bytes to an
OsStr
without cost.)
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let os_str = b"foo".to_os_str().expect("should be valid UTF-8");
assert_eq!(os_str, "foo");
fn to_os_str_lossy(&self) -> Cow<'_, OsStr>
fn to_os_str_lossy(&self) -> Cow<'_, OsStr>
Lossily create an OS string slice from this byte string.
When OS strings can be constructed from arbitrary byte sequences, this is zero cost and always returns a slice. Otherwise, this will perform a UTF-8 check and lossily convert this byte string into valid UTF-8 using the Unicode replacement codepoint.
Note that this can prevent the correct roundtripping of file paths when
the representation of OsStr
is opaque.
§Examples
Basic usage:
use bstr::ByteSlice;
let os_str = b"foo\xFFbar".to_os_str_lossy();
assert_eq!(os_str.to_string_lossy(), "foo\u{FFFD}bar");
fn to_path(&self) -> Result<&Path, Utf8Error>
fn to_path(&self) -> Result<&Path, Utf8Error>
Create a path slice from this byte string.
When paths can be constructed from arbitrary byte sequences, this
always succeeds and is zero cost. Otherwise, this returns a UTF-8
decoding error if this byte string is not valid UTF-8. (For example,
assuming the representation of Path
is opaque on Windows, file paths
are allowed to be a sequence of arbitrary 16-bit integers. There is
no obvious mapping from an arbitrary sequence of 8-bit integers to an
arbitrary sequence of 16-bit integers. If the representation of Path
is even opened up, then this will convert any sequence of bytes to an
Path
without cost.)
§Examples
Basic usage:
use bstr::ByteSlice;
let path = b"foo".to_path().expect("should be valid UTF-8");
assert_eq!(path.as_os_str(), "foo");
fn to_path_lossy(&self) -> Cow<'_, Path>
fn to_path_lossy(&self) -> Cow<'_, Path>
Lossily create a path slice from this byte string.
When paths can be constructed from arbitrary byte sequences, this is zero cost and always returns a slice. Otherwise, this will perform a UTF-8 check and lossily convert this byte string into valid UTF-8 using the Unicode replacement codepoint.
Note that this can prevent the correct roundtripping of file paths when
the representation of Path
is opaque.
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = b"foo\xFFbar";
let path = bs.to_path_lossy();
assert_eq!(path.to_string_lossy(), "foo\u{FFFD}bar");
fn contains_str<B>(&self, needle: B) -> bool
fn contains_str<B>(&self, needle: B) -> bool
Returns true if and only if this byte string contains the given needle.
§Examples
Basic usage:
use bstr::ByteSlice;
assert!(b"foo bar".contains_str("foo"));
assert!(b"foo bar".contains_str("bar"));
assert!(!b"foo".contains_str("foobar"));
fn starts_with_str<B>(&self, prefix: B) -> bool
fn starts_with_str<B>(&self, prefix: B) -> bool
Returns true if and only if this byte string has the given prefix.
§Examples
Basic usage:
use bstr::ByteSlice;
assert!(b"foo bar".starts_with_str("foo"));
assert!(!b"foo bar".starts_with_str("bar"));
assert!(!b"foo".starts_with_str("foobar"));
fn ends_with_str<B>(&self, suffix: B) -> bool
fn ends_with_str<B>(&self, suffix: B) -> bool
Returns true if and only if this byte string has the given suffix.
§Examples
Basic usage:
use bstr::ByteSlice;
assert!(b"foo bar".ends_with_str("bar"));
assert!(!b"foo bar".ends_with_str("foo"));
assert!(!b"bar".ends_with_str("foobar"));
fn find<B>(&self, needle: B) -> Option<usize>
fn find<B>(&self, needle: B) -> Option<usize>
Returns the index of the first occurrence of the given needle.
The needle may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
Note that if you’re are searching for the same needle in many
different small haystacks, it may be faster to initialize a
Finder
once, and reuse it for each search.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the needle and the haystack. That is, this runs
in O(needle.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"foo bar baz";
assert_eq!(Some(0), s.find("foo"));
assert_eq!(Some(4), s.find("bar"));
assert_eq!(None, s.find("quux"));
fn rfind<B>(&self, needle: B) -> Option<usize>
fn rfind<B>(&self, needle: B) -> Option<usize>
Returns the index of the last occurrence of the given needle.
The needle may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
Note that if you’re are searching for the same needle in many
different small haystacks, it may be faster to initialize a
FinderReverse
once, and reuse it for
each search.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the needle and the haystack. That is, this runs
in O(needle.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"foo bar baz";
assert_eq!(Some(0), s.rfind("foo"));
assert_eq!(Some(4), s.rfind("bar"));
assert_eq!(Some(8), s.rfind("ba"));
assert_eq!(None, s.rfind("quux"));
fn find_iter<'h, 'n, B>(&'h self, needle: &'n B) -> Find<'h, 'n>
fn find_iter<'h, 'n, B>(&'h self, needle: &'n B) -> Find<'h, 'n>
Returns an iterator of the non-overlapping occurrences of the given needle. The iterator yields byte offset positions indicating the start of each match.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the needle and the haystack. That is, this runs
in O(needle.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"foo bar foo foo quux foo";
let matches: Vec<usize> = s.find_iter("foo").collect();
assert_eq!(matches, vec![0, 8, 12, 21]);
An empty string matches at every position, including the position immediately following the last byte:
use bstr::ByteSlice;
let matches: Vec<usize> = b"foo".find_iter("").collect();
assert_eq!(matches, vec![0, 1, 2, 3]);
let matches: Vec<usize> = b"".find_iter("").collect();
assert_eq!(matches, vec![0]);
fn rfind_iter<'h, 'n, B>(&'h self, needle: &'n B) -> FindReverse<'h, 'n>
fn rfind_iter<'h, 'n, B>(&'h self, needle: &'n B) -> FindReverse<'h, 'n>
Returns an iterator of the non-overlapping occurrences of the given needle in reverse. The iterator yields byte offset positions indicating the start of each match.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the needle and the haystack. That is, this runs
in O(needle.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"foo bar foo foo quux foo";
let matches: Vec<usize> = s.rfind_iter("foo").collect();
assert_eq!(matches, vec![21, 12, 8, 0]);
An empty string matches at every position, including the position immediately following the last byte:
use bstr::ByteSlice;
let matches: Vec<usize> = b"foo".rfind_iter("").collect();
assert_eq!(matches, vec![3, 2, 1, 0]);
let matches: Vec<usize> = b"".rfind_iter("").collect();
assert_eq!(matches, vec![0]);
fn find_byte(&self, byte: u8) -> Option<usize>
fn find_byte(&self, byte: u8) -> Option<usize>
Returns the index of the first occurrence of the given byte. If the
byte does not occur in this byte string, then None
is returned.
§Examples
Basic usage:
use bstr::ByteSlice;
assert_eq!(Some(10), b"foo bar baz".find_byte(b'z'));
assert_eq!(None, b"foo bar baz".find_byte(b'y'));
fn rfind_byte(&self, byte: u8) -> Option<usize>
fn rfind_byte(&self, byte: u8) -> Option<usize>
Returns the index of the last occurrence of the given byte. If the
byte does not occur in this byte string, then None
is returned.
§Examples
Basic usage:
use bstr::ByteSlice;
assert_eq!(Some(10), b"foo bar baz".rfind_byte(b'z'));
assert_eq!(None, b"foo bar baz".rfind_byte(b'y'));
fn find_char(&self, ch: char) -> Option<usize>
fn find_char(&self, ch: char) -> Option<usize>
Returns the index of the first occurrence of the given codepoint.
If the codepoint does not occur in this byte string, then None
is
returned.
Note that if one searches for the replacement codepoint, \u{FFFD}
,
then only explicit occurrences of that encoding will be found. Invalid
UTF-8 sequences will not be matched.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
assert_eq!(Some(10), b"foo bar baz".find_char('z'));
assert_eq!(Some(4), B("αβγγδ").find_char('γ'));
assert_eq!(None, b"foo bar baz".find_char('y'));
fn rfind_char(&self, ch: char) -> Option<usize>
fn rfind_char(&self, ch: char) -> Option<usize>
Returns the index of the last occurrence of the given codepoint.
If the codepoint does not occur in this byte string, then None
is
returned.
Note that if one searches for the replacement codepoint, \u{FFFD}
,
then only explicit occurrences of that encoding will be found. Invalid
UTF-8 sequences will not be matched.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
assert_eq!(Some(10), b"foo bar baz".rfind_char('z'));
assert_eq!(Some(6), B("αβγγδ").rfind_char('γ'));
assert_eq!(None, b"foo bar baz".rfind_char('y'));
fn find_byteset<B>(&self, byteset: B) -> Option<usize>
fn find_byteset<B>(&self, byteset: B) -> Option<usize>
Returns the index of the first occurrence of any of the bytes in the provided set.
The byteset
may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
, but
note that passing a &str
which contains multibyte characters may not
behave as you expect: each byte in the &str
is treated as an
individual member of the byte set.
Note that order is irrelevant for the byteset
parameter, and
duplicate bytes present in its body are ignored.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the set of bytes and the haystack. That is, this
runs in O(byteset.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
assert_eq!(b"foo bar baz".find_byteset(b"zr"), Some(6));
assert_eq!(b"foo baz bar".find_byteset(b"bzr"), Some(4));
assert_eq!(None, b"foo baz bar".find_byteset(b"\t\n"));
// The empty byteset never matches.
assert_eq!(None, b"abc".find_byteset(b""));
assert_eq!(None, b"".find_byteset(b""));
fn find_not_byteset<B>(&self, byteset: B) -> Option<usize>
fn find_not_byteset<B>(&self, byteset: B) -> Option<usize>
Returns the index of the first occurrence of a byte that is not a member of the provided set.
The byteset
may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
, but
note that passing a &str
which contains multibyte characters may not
behave as you expect: each byte in the &str
is treated as an
individual member of the byte set.
Note that order is irrelevant for the byteset
parameter, and
duplicate bytes present in its body are ignored.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the set of bytes and the haystack. That is, this
runs in O(byteset.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
assert_eq!(b"foo bar baz".find_not_byteset(b"fo "), Some(4));
assert_eq!(b"\t\tbaz bar".find_not_byteset(b" \t\r\n"), Some(2));
assert_eq!(b"foo\nbaz\tbar".find_not_byteset(b"\t\n"), Some(0));
// The negation of the empty byteset matches everything.
assert_eq!(Some(0), b"abc".find_not_byteset(b""));
// But an empty string never contains anything.
assert_eq!(None, b"".find_not_byteset(b""));
fn rfind_byteset<B>(&self, byteset: B) -> Option<usize>
fn rfind_byteset<B>(&self, byteset: B) -> Option<usize>
Returns the index of the last occurrence of any of the bytes in the provided set.
The byteset
may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
, but
note that passing a &str
which contains multibyte characters may not
behave as you expect: each byte in the &str
is treated as an
individual member of the byte set.
Note that order is irrelevant for the byteset
parameter, and duplicate
bytes present in its body are ignored.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the set of bytes and the haystack. That is, this
runs in O(byteset.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
assert_eq!(b"foo bar baz".rfind_byteset(b"agb"), Some(9));
assert_eq!(b"foo baz bar".rfind_byteset(b"rabz "), Some(10));
assert_eq!(b"foo baz bar".rfind_byteset(b"\n123"), None);
fn rfind_not_byteset<B>(&self, byteset: B) -> Option<usize>
fn rfind_not_byteset<B>(&self, byteset: B) -> Option<usize>
Returns the index of the last occurrence of a byte that is not a member of the provided set.
The byteset
may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
, but
note that passing a &str
which contains multibyte characters may not
behave as you expect: each byte in the &str
is treated as an
individual member of the byte set.
Note that order is irrelevant for the byteset
parameter, and
duplicate bytes present in its body are ignored.
§Complexity
This routine is guaranteed to have worst case linear time complexity
with respect to both the set of bytes and the haystack. That is, this
runs in O(byteset.len() + haystack.len())
time.
This routine is also guaranteed to have worst case constant space complexity.
§Examples
Basic usage:
use bstr::ByteSlice;
assert_eq!(b"foo bar baz,\t".rfind_not_byteset(b",\t"), Some(10));
assert_eq!(b"foo baz bar".rfind_not_byteset(b"rabz "), Some(2));
assert_eq!(None, b"foo baz bar".rfind_not_byteset(b"barfoz "));
fn fields(&self) -> Fields<'_>
fn fields(&self) -> Fields<'_>
Returns an iterator over the fields in a byte string, separated
by contiguous whitespace (according to the Unicode property
White_Space
).
§Example
Basic usage:
use bstr::{B, ByteSlice};
let s = B(" foo\tbar\t\u{2003}\nquux \n");
let fields: Vec<&[u8]> = s.fields().collect();
assert_eq!(fields, vec![B("foo"), B("bar"), B("quux")]);
A byte string consisting of just whitespace yields no elements:
use bstr::{B, ByteSlice};
assert_eq!(0, B(" \n\t\u{2003}\n \t").fields().count());
fn fields_with<F>(&self, f: F) -> FieldsWith<'_, F>
fn fields_with<F>(&self, f: F) -> FieldsWith<'_, F>
Returns an iterator over the fields in a byte string, separated by contiguous codepoints satisfying the given predicate.
If this byte string is not valid UTF-8, then the given closure will be called with a Unicode replacement codepoint when invalid UTF-8 bytes are seen.
§Example
Basic usage:
use bstr::{B, ByteSlice};
let s = b"123foo999999bar1quux123456";
let fields: Vec<&[u8]> = s.fields_with(|c| c.is_numeric()).collect();
assert_eq!(fields, vec![B("foo"), B("bar"), B("quux")]);
A byte string consisting of all codepoints satisfying the predicate yields no elements:
use bstr::ByteSlice;
assert_eq!(0, b"1911354563".fields_with(|c| c.is_numeric()).count());
fn split_str<'h, 's, B>(&'h self, splitter: &'s B) -> Split<'h, 's>
fn split_str<'h, 's, B>(&'h self, splitter: &'s B) -> Split<'h, 's>
Returns an iterator over substrings of this byte string, separated by the given byte string. Each element yielded is guaranteed not to include the splitter substring.
The splitter may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b"Mary had a little lamb".split_str(" ").collect();
assert_eq!(x, vec![
B("Mary"), B("had"), B("a"), B("little"), B("lamb"),
]);
let x: Vec<&[u8]> = b"".split_str("X").collect();
assert_eq!(x, vec![b""]);
let x: Vec<&[u8]> = b"lionXXtigerXleopard".split_str("X").collect();
assert_eq!(x, vec![B("lion"), B(""), B("tiger"), B("leopard")]);
let x: Vec<&[u8]> = b"lion::tiger::leopard".split_str("::").collect();
assert_eq!(x, vec![B("lion"), B("tiger"), B("leopard")]);
If a string contains multiple contiguous separators, you will end up with empty strings yielded by the iterator:
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b"||||a||b|c".split_str("|").collect();
assert_eq!(x, vec![
B(""), B(""), B(""), B(""), B("a"), B(""), B("b"), B("c"),
]);
let x: Vec<&[u8]> = b"(///)".split_str("/").collect();
assert_eq!(x, vec![B("("), B(""), B(""), B(")")]);
Separators at the start or end of a string are neighbored by empty strings.
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b"010".split_str("0").collect();
assert_eq!(x, vec![B(""), B("1"), B("")]);
When the empty string is used as a separator, it splits every byte in the byte string, along with the beginning and end of the byte string.
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b"rust".split_str("").collect();
assert_eq!(x, vec![
B(""), B("r"), B("u"), B("s"), B("t"), B(""),
]);
// Splitting by an empty string is not UTF-8 aware. Elements yielded
// may not be valid UTF-8!
let x: Vec<&[u8]> = B("☃").split_str("").collect();
assert_eq!(x, vec![
B(""), B(b"\xE2"), B(b"\x98"), B(b"\x83"), B(""),
]);
Contiguous separators, especially whitespace, can lead to possibly surprising behavior. For example, this code is correct:
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b" a b c".split_str(" ").collect();
assert_eq!(x, vec![
B(""), B(""), B(""), B(""), B("a"), B(""), B("b"), B("c"),
]);
It does not give you ["a", "b", "c"]
. For that behavior, use
fields
instead.
fn rsplit_str<'h, 's, B>(&'h self, splitter: &'s B) -> SplitReverse<'h, 's>
fn rsplit_str<'h, 's, B>(&'h self, splitter: &'s B) -> SplitReverse<'h, 's>
Returns an iterator over substrings of this byte string, separated by the given byte string, in reverse. Each element yielded is guaranteed not to include the splitter substring.
The splitter may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> =
b"Mary had a little lamb".rsplit_str(" ").collect();
assert_eq!(x, vec![
B("lamb"), B("little"), B("a"), B("had"), B("Mary"),
]);
let x: Vec<&[u8]> = b"".rsplit_str("X").collect();
assert_eq!(x, vec![b""]);
let x: Vec<&[u8]> = b"lionXXtigerXleopard".rsplit_str("X").collect();
assert_eq!(x, vec![B("leopard"), B("tiger"), B(""), B("lion")]);
let x: Vec<&[u8]> = b"lion::tiger::leopard".rsplit_str("::").collect();
assert_eq!(x, vec![B("leopard"), B("tiger"), B("lion")]);
If a string contains multiple contiguous separators, you will end up with empty strings yielded by the iterator:
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b"||||a||b|c".rsplit_str("|").collect();
assert_eq!(x, vec![
B("c"), B("b"), B(""), B("a"), B(""), B(""), B(""), B(""),
]);
let x: Vec<&[u8]> = b"(///)".rsplit_str("/").collect();
assert_eq!(x, vec![B(")"), B(""), B(""), B("(")]);
Separators at the start or end of a string are neighbored by empty strings.
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b"010".rsplit_str("0").collect();
assert_eq!(x, vec![B(""), B("1"), B("")]);
When the empty string is used as a separator, it splits every byte in the byte string, along with the beginning and end of the byte string.
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b"rust".rsplit_str("").collect();
assert_eq!(x, vec![
B(""), B("t"), B("s"), B("u"), B("r"), B(""),
]);
// Splitting by an empty string is not UTF-8 aware. Elements yielded
// may not be valid UTF-8!
let x: Vec<&[u8]> = B("☃").rsplit_str("").collect();
assert_eq!(x, vec![B(""), B(b"\x83"), B(b"\x98"), B(b"\xE2"), B("")]);
Contiguous separators, especially whitespace, can lead to possibly surprising behavior. For example, this code is correct:
use bstr::{B, ByteSlice};
let x: Vec<&[u8]> = b" a b c".rsplit_str(" ").collect();
assert_eq!(x, vec![
B("c"), B("b"), B(""), B("a"), B(""), B(""), B(""), B(""),
]);
It does not give you ["a", "b", "c"]
.
fn split_once_str<'a, B>(&'a self, splitter: &B) -> Option<(&'a [u8], &'a [u8])>
fn split_once_str<'a, B>(&'a self, splitter: &B) -> Option<(&'a [u8], &'a [u8])>
Split this byte string at the first occurrence of splitter
.
If the splitter
is found in the byte string, returns a tuple
containing the parts of the string before and after the first occurrence
of splitter
respectively. Otherwise, if there are no occurrences of
splitter
in the byte string, returns None
.
The splitter may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
If you need to split on the last instance of a delimiter instead, see
the ByteSlice::rsplit_once_str
method .
§Examples
Basic usage:
use bstr::{B, ByteSlice};
assert_eq!(
B("foo,bar").split_once_str(","),
Some((B("foo"), B("bar"))),
);
assert_eq!(
B("foo,bar,baz").split_once_str(","),
Some((B("foo"), B("bar,baz"))),
);
assert_eq!(B("foo").split_once_str(","), None);
assert_eq!(B("foo,").split_once_str(b","), Some((B("foo"), B(""))));
assert_eq!(B(",foo").split_once_str(b","), Some((B(""), B("foo"))));
fn rsplit_once_str<'a, B>(
&'a self,
splitter: &B,
) -> Option<(&'a [u8], &'a [u8])>
fn rsplit_once_str<'a, B>( &'a self, splitter: &B, ) -> Option<(&'a [u8], &'a [u8])>
Split this byte string at the last occurrence of splitter
.
If the splitter
is found in the byte string, returns a tuple
containing the parts of the string before and after the last occurrence
of splitter
, respectively. Otherwise, if there are no occurrences of
splitter
in the byte string, returns None
.
The splitter may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
If you need to split on the first instance of a delimiter instead, see
the ByteSlice::split_once_str
method.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
assert_eq!(
B("foo,bar").rsplit_once_str(","),
Some((B("foo"), B("bar"))),
);
assert_eq!(
B("foo,bar,baz").rsplit_once_str(","),
Some((B("foo,bar"), B("baz"))),
);
assert_eq!(B("foo").rsplit_once_str(","), None);
assert_eq!(B("foo,").rsplit_once_str(b","), Some((B("foo"), B(""))));
assert_eq!(B(",foo").rsplit_once_str(b","), Some((B(""), B("foo"))));
fn splitn_str<'h, 's, B>(
&'h self,
limit: usize,
splitter: &'s B,
) -> SplitN<'h, 's>
fn splitn_str<'h, 's, B>( &'h self, limit: usize, splitter: &'s B, ) -> SplitN<'h, 's>
Returns an iterator of at most limit
substrings of this byte string,
separated by the given byte string. If limit
substrings are yielded,
then the last substring will contain the remainder of this byte string.
The needle may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let x: Vec<_> = b"Mary had a little lamb".splitn_str(3, " ").collect();
assert_eq!(x, vec![B("Mary"), B("had"), B("a little lamb")]);
let x: Vec<_> = b"".splitn_str(3, "X").collect();
assert_eq!(x, vec![b""]);
let x: Vec<_> = b"lionXXtigerXleopard".splitn_str(3, "X").collect();
assert_eq!(x, vec![B("lion"), B(""), B("tigerXleopard")]);
let x: Vec<_> = b"lion::tiger::leopard".splitn_str(2, "::").collect();
assert_eq!(x, vec![B("lion"), B("tiger::leopard")]);
let x: Vec<_> = b"abcXdef".splitn_str(1, "X").collect();
assert_eq!(x, vec![B("abcXdef")]);
let x: Vec<_> = b"abcdef".splitn_str(2, "X").collect();
assert_eq!(x, vec![B("abcdef")]);
let x: Vec<_> = b"abcXdef".splitn_str(0, "X").collect();
assert!(x.is_empty());
fn rsplitn_str<'h, 's, B>(
&'h self,
limit: usize,
splitter: &'s B,
) -> SplitNReverse<'h, 's>
fn rsplitn_str<'h, 's, B>( &'h self, limit: usize, splitter: &'s B, ) -> SplitNReverse<'h, 's>
Returns an iterator of at most limit
substrings of this byte string,
separated by the given byte string, in reverse. If limit
substrings
are yielded, then the last substring will contain the remainder of this
byte string.
The needle may be any type that can be cheaply converted into a
&[u8]
. This includes, but is not limited to, &str
and &[u8]
.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let x: Vec<_> =
b"Mary had a little lamb".rsplitn_str(3, " ").collect();
assert_eq!(x, vec![B("lamb"), B("little"), B("Mary had a")]);
let x: Vec<_> = b"".rsplitn_str(3, "X").collect();
assert_eq!(x, vec![b""]);
let x: Vec<_> = b"lionXXtigerXleopard".rsplitn_str(3, "X").collect();
assert_eq!(x, vec![B("leopard"), B("tiger"), B("lionX")]);
let x: Vec<_> = b"lion::tiger::leopard".rsplitn_str(2, "::").collect();
assert_eq!(x, vec![B("leopard"), B("lion::tiger")]);
let x: Vec<_> = b"abcXdef".rsplitn_str(1, "X").collect();
assert_eq!(x, vec![B("abcXdef")]);
let x: Vec<_> = b"abcdef".rsplitn_str(2, "X").collect();
assert_eq!(x, vec![B("abcdef")]);
let x: Vec<_> = b"abcXdef".rsplitn_str(0, "X").collect();
assert!(x.is_empty());
fn replace<N, R>(&self, needle: N, replacement: R) -> Vec<u8> ⓘ
fn replace<N, R>(&self, needle: N, replacement: R) -> Vec<u8> ⓘ
Replace all matches of the given needle with the given replacement, and
the result as a new Vec<u8>
.
This routine is useful as a convenience. If you need to reuse an
allocation, use replace_into
instead.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"this is old".replace("old", "new");
assert_eq!(s, "this is new".as_bytes());
When the pattern doesn’t match:
use bstr::ByteSlice;
let s = b"this is old".replace("nada nada", "limonada");
assert_eq!(s, "this is old".as_bytes());
When the needle is an empty string:
use bstr::ByteSlice;
let s = b"foo".replace("", "Z");
assert_eq!(s, "ZfZoZoZ".as_bytes());
fn replacen<N, R>(&self, needle: N, replacement: R, limit: usize) -> Vec<u8> ⓘ
fn replacen<N, R>(&self, needle: N, replacement: R, limit: usize) -> Vec<u8> ⓘ
Replace up to limit
matches of the given needle with the given
replacement, and the result as a new Vec<u8>
.
This routine is useful as a convenience. If you need to reuse an
allocation, use replacen_into
instead.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"foofoo".replacen("o", "z", 2);
assert_eq!(s, "fzzfoo".as_bytes());
When the pattern doesn’t match:
use bstr::ByteSlice;
let s = b"foofoo".replacen("a", "z", 2);
assert_eq!(s, "foofoo".as_bytes());
When the needle is an empty string:
use bstr::ByteSlice;
let s = b"foo".replacen("", "Z", 2);
assert_eq!(s, "ZfZoo".as_bytes());
fn replace_into<N, R>(&self, needle: N, replacement: R, dest: &mut Vec<u8>)
fn replace_into<N, R>(&self, needle: N, replacement: R, dest: &mut Vec<u8>)
Replace all matches of the given needle with the given replacement,
and write the result into the provided Vec<u8>
.
This does not clear dest
before writing to it.
This routine is useful for reusing allocation. For a more convenient
API, use replace
instead.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"this is old";
let mut dest = vec![];
s.replace_into("old", "new", &mut dest);
assert_eq!(dest, "this is new".as_bytes());
When the pattern doesn’t match:
use bstr::ByteSlice;
let s = b"this is old";
let mut dest = vec![];
s.replace_into("nada nada", "limonada", &mut dest);
assert_eq!(dest, "this is old".as_bytes());
When the needle is an empty string:
use bstr::ByteSlice;
let s = b"foo";
let mut dest = vec![];
s.replace_into("", "Z", &mut dest);
assert_eq!(dest, "ZfZoZoZ".as_bytes());
fn replacen_into<N, R>(
&self,
needle: N,
replacement: R,
limit: usize,
dest: &mut Vec<u8>,
)
fn replacen_into<N, R>( &self, needle: N, replacement: R, limit: usize, dest: &mut Vec<u8>, )
Replace up to limit
matches of the given needle with the given
replacement, and write the result into the provided Vec<u8>
.
This does not clear dest
before writing to it.
This routine is useful for reusing allocation. For a more convenient
API, use replacen
instead.
§Examples
Basic usage:
use bstr::ByteSlice;
let s = b"foofoo";
let mut dest = vec![];
s.replacen_into("o", "z", 2, &mut dest);
assert_eq!(dest, "fzzfoo".as_bytes());
When the pattern doesn’t match:
use bstr::ByteSlice;
let s = b"foofoo";
let mut dest = vec![];
s.replacen_into("a", "z", 2, &mut dest);
assert_eq!(dest, "foofoo".as_bytes());
When the needle is an empty string:
use bstr::ByteSlice;
let s = b"foo";
let mut dest = vec![];
s.replacen_into("", "Z", 2, &mut dest);
assert_eq!(dest, "ZfZoo".as_bytes());
fn bytes(&self) -> Bytes<'_>
fn bytes(&self) -> Bytes<'_>
Returns an iterator over the bytes in this byte string.
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = b"foobar";
let bytes: Vec<u8> = bs.bytes().collect();
assert_eq!(bytes, bs);
fn chars(&self) -> Chars<'_>
fn chars(&self) -> Chars<'_>
Returns an iterator over the Unicode scalar values in this byte string. If invalid UTF-8 is encountered, then the Unicode replacement codepoint is yielded instead.
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = b"\xE2\x98\x83\xFF\xF0\x9D\x9E\x83\xE2\x98\x61";
let chars: Vec<char> = bs.chars().collect();
assert_eq!(vec!['☃', '\u{FFFD}', '𝞃', '\u{FFFD}', 'a'], chars);
Codepoints can also be iterated over in reverse:
use bstr::ByteSlice;
let bs = b"\xE2\x98\x83\xFF\xF0\x9D\x9E\x83\xE2\x98\x61";
let chars: Vec<char> = bs.chars().rev().collect();
assert_eq!(vec!['a', '\u{FFFD}', '𝞃', '\u{FFFD}', '☃'], chars);
fn char_indices(&self) -> CharIndices<'_>
fn char_indices(&self) -> CharIndices<'_>
Returns an iterator over the Unicode scalar values in this byte string along with their starting and ending byte index positions. If invalid UTF-8 is encountered, then the Unicode replacement codepoint is yielded instead.
Note that this is slightly different from the CharIndices
iterator
provided by the standard library. Aside from working on possibly
invalid UTF-8, this iterator provides both the corresponding starting
and ending byte indices of each codepoint yielded. The ending position
is necessary to slice the original byte string when invalid UTF-8 bytes
are converted into a Unicode replacement codepoint, since a single
replacement codepoint can substitute anywhere from 1 to 3 invalid bytes
(inclusive).
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = b"\xE2\x98\x83\xFF\xF0\x9D\x9E\x83\xE2\x98\x61";
let chars: Vec<(usize, usize, char)> = bs.char_indices().collect();
assert_eq!(chars, vec![
(0, 3, '☃'),
(3, 4, '\u{FFFD}'),
(4, 8, '𝞃'),
(8, 10, '\u{FFFD}'),
(10, 11, 'a'),
]);
Codepoints can also be iterated over in reverse:
use bstr::ByteSlice;
let bs = b"\xE2\x98\x83\xFF\xF0\x9D\x9E\x83\xE2\x98\x61";
let chars: Vec<(usize, usize, char)> = bs
.char_indices()
.rev()
.collect();
assert_eq!(chars, vec![
(10, 11, 'a'),
(8, 10, '\u{FFFD}'),
(4, 8, '𝞃'),
(3, 4, '\u{FFFD}'),
(0, 3, '☃'),
]);
fn utf8_chunks(&self) -> Utf8Chunks<'_>
fn utf8_chunks(&self) -> Utf8Chunks<'_>
Iterate over chunks of valid UTF-8.
The iterator returned yields chunks of valid UTF-8 separated by invalid
UTF-8 bytes, if they exist. Invalid UTF-8 bytes are always 1-3 bytes,
which are determined via the “substitution of maximal subparts”
strategy described in the docs for the
ByteSlice::to_str_lossy
method.
§Examples
This example shows how to gather all valid and invalid chunks from a byte slice:
use bstr::{ByteSlice, Utf8Chunk};
let bytes = b"foo\xFD\xFEbar\xFF";
let (mut valid_chunks, mut invalid_chunks) = (vec![], vec![]);
for chunk in bytes.utf8_chunks() {
if !chunk.valid().is_empty() {
valid_chunks.push(chunk.valid());
}
if !chunk.invalid().is_empty() {
invalid_chunks.push(chunk.invalid());
}
}
assert_eq!(valid_chunks, vec!["foo", "bar"]);
assert_eq!(invalid_chunks, vec![b"\xFD", b"\xFE", b"\xFF"]);
fn graphemes(&self) -> Graphemes<'_>
fn graphemes(&self) -> Graphemes<'_>
Returns an iterator over the grapheme clusters in this byte string. If invalid UTF-8 is encountered, then the Unicode replacement codepoint is yielded instead.
§Examples
This example shows how multiple codepoints can combine to form a single grapheme cluster:
use bstr::ByteSlice;
let bs = "a\u{0300}\u{0316}\u{1F1FA}\u{1F1F8}".as_bytes();
let graphemes: Vec<&str> = bs.graphemes().collect();
assert_eq!(vec!["à̖", "🇺🇸"], graphemes);
This shows that graphemes can be iterated over in reverse:
use bstr::ByteSlice;
let bs = "a\u{0300}\u{0316}\u{1F1FA}\u{1F1F8}".as_bytes();
let graphemes: Vec<&str> = bs.graphemes().rev().collect();
assert_eq!(vec!["🇺🇸", "à̖"], graphemes);
fn grapheme_indices(&self) -> GraphemeIndices<'_>
fn grapheme_indices(&self) -> GraphemeIndices<'_>
Returns an iterator over the grapheme clusters in this byte string along with their starting and ending byte index positions. If invalid UTF-8 is encountered, then the Unicode replacement codepoint is yielded instead.
§Examples
This example shows how to get the byte offsets of each individual grapheme cluster:
use bstr::ByteSlice;
let bs = "a\u{0300}\u{0316}\u{1F1FA}\u{1F1F8}".as_bytes();
let graphemes: Vec<(usize, usize, &str)> =
bs.grapheme_indices().collect();
assert_eq!(vec![(0, 5, "à̖"), (5, 13, "🇺🇸")], graphemes);
This example shows what happens when invalid UTF-8 is encountered. Note
that the offsets are valid indices into the original string, and do
not necessarily correspond to the length of the &str
returned!
use bstr::{ByteSlice, ByteVec};
let mut bytes = vec![];
bytes.push_str("a\u{0300}\u{0316}");
bytes.push(b'\xFF');
bytes.push_str("\u{1F1FA}\u{1F1F8}");
let graphemes: Vec<(usize, usize, &str)> =
bytes.grapheme_indices().collect();
assert_eq!(
graphemes,
vec![(0, 5, "à̖"), (5, 6, "\u{FFFD}"), (6, 14, "🇺🇸")]
);
fn words(&self) -> Words<'_>
fn words(&self) -> Words<'_>
Returns an iterator over the words in this byte string. If invalid UTF-8 is encountered, then the Unicode replacement codepoint is yielded instead.
This is similar to
words_with_breaks
,
except it only returns elements that contain a “word” character. A word
character is defined by UTS #18 (Annex C) to be the combination of the
Alphabetic
and Join_Control
properties, along with the
Decimal_Number
, Mark
and Connector_Punctuation
general
categories.
Since words are made up of one or more codepoints, this iterator
yields &str
elements. When invalid UTF-8 is encountered, replacement
codepoints are substituted.
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = br#"The quick ("brown") fox can't jump 32.3 feet, right?"#;
let words: Vec<&str> = bs.words().collect();
assert_eq!(words, vec![
"The", "quick", "brown", "fox", "can't",
"jump", "32.3", "feet", "right",
]);
fn word_indices(&self) -> WordIndices<'_>
fn word_indices(&self) -> WordIndices<'_>
Returns an iterator over the words in this byte string along with their starting and ending byte index positions.
This is similar to
words_with_break_indices
,
except it only returns elements that contain a “word” character. A word
character is defined by UTS #18 (Annex C) to be the combination of the
Alphabetic
and Join_Control
properties, along with the
Decimal_Number
, Mark
and Connector_Punctuation
general
categories.
Since words are made up of one or more codepoints, this iterator
yields &str
elements. When invalid UTF-8 is encountered, replacement
codepoints are substituted.
§Examples
This example shows how to get the byte offsets of each individual word:
use bstr::ByteSlice;
let bs = b"can't jump 32.3 feet";
let words: Vec<(usize, usize, &str)> = bs.word_indices().collect();
assert_eq!(words, vec![
(0, 5, "can't"),
(6, 10, "jump"),
(11, 15, "32.3"),
(16, 20, "feet"),
]);
fn words_with_breaks(&self) -> WordsWithBreaks<'_>
fn words_with_breaks(&self) -> WordsWithBreaks<'_>
Returns an iterator over the words in this byte string, along with all breaks between the words. Concatenating all elements yielded by the iterator results in the original string (modulo Unicode replacement codepoint substitutions if invalid UTF-8 is encountered).
Since words are made up of one or more codepoints, this iterator
yields &str
elements. When invalid UTF-8 is encountered, replacement
codepoints are substituted.
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = br#"The quick ("brown") fox can't jump 32.3 feet, right?"#;
let words: Vec<&str> = bs.words_with_breaks().collect();
assert_eq!(words, vec![
"The", " ", "quick", " ", "(", "\"", "brown", "\"", ")",
" ", "fox", " ", "can't", " ", "jump", " ", "32.3", " ", "feet",
",", " ", "right", "?",
]);
fn words_with_break_indices(&self) -> WordsWithBreakIndices<'_>
fn words_with_break_indices(&self) -> WordsWithBreakIndices<'_>
Returns an iterator over the words and their byte offsets in this byte string, along with all breaks between the words. Concatenating all elements yielded by the iterator results in the original string (modulo Unicode replacement codepoint substitutions if invalid UTF-8 is encountered).
Since words are made up of one or more codepoints, this iterator
yields &str
elements. When invalid UTF-8 is encountered, replacement
codepoints are substituted.
§Examples
This example shows how to get the byte offsets of each individual word:
use bstr::ByteSlice;
let bs = b"can't jump 32.3 feet";
let words: Vec<(usize, usize, &str)> =
bs.words_with_break_indices().collect();
assert_eq!(words, vec![
(0, 5, "can't"),
(5, 6, " "),
(6, 10, "jump"),
(10, 11, " "),
(11, 15, "32.3"),
(15, 16, " "),
(16, 20, "feet"),
]);
fn sentences(&self) -> Sentences<'_>
fn sentences(&self) -> Sentences<'_>
Returns an iterator over the sentences in this byte string.
Typically, a sentence will include its trailing punctuation and whitespace. Concatenating all elements yielded by the iterator results in the original string (modulo Unicode replacement codepoint substitutions if invalid UTF-8 is encountered).
Since sentences are made up of one or more codepoints, this iterator
yields &str
elements. When invalid UTF-8 is encountered, replacement
codepoints are substituted.
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = b"I want this. Not that. Right now.";
let sentences: Vec<&str> = bs.sentences().collect();
assert_eq!(sentences, vec![
"I want this. ",
"Not that. ",
"Right now.",
]);
fn sentence_indices(&self) -> SentenceIndices<'_>
fn sentence_indices(&self) -> SentenceIndices<'_>
Returns an iterator over the sentences in this byte string along with their starting and ending byte index positions.
Typically, a sentence will include its trailing punctuation and whitespace. Concatenating all elements yielded by the iterator results in the original string (modulo Unicode replacement codepoint substitutions if invalid UTF-8 is encountered).
Since sentences are made up of one or more codepoints, this iterator
yields &str
elements. When invalid UTF-8 is encountered, replacement
codepoints are substituted.
§Examples
Basic usage:
use bstr::ByteSlice;
let bs = b"I want this. Not that. Right now.";
let sentences: Vec<(usize, usize, &str)> =
bs.sentence_indices().collect();
assert_eq!(sentences, vec![
(0, 13, "I want this. "),
(13, 23, "Not that. "),
(23, 33, "Right now."),
]);
fn lines(&self) -> Lines<'_>
fn lines(&self) -> Lines<'_>
An iterator over all lines in a byte string, without their terminators.
For this iterator, the only line terminators recognized are \r\n
and
\n
.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = b"\
foo
bar\r
baz
quux";
let lines: Vec<&[u8]> = s.lines().collect();
assert_eq!(lines, vec![
B("foo"), B(""), B("bar"), B("baz"), B(""), B(""), B("quux"),
]);
fn lines_with_terminator(&self) -> LinesWithTerminator<'_>
fn lines_with_terminator(&self) -> LinesWithTerminator<'_>
An iterator over all lines in a byte string, including their terminators.
For this iterator, the only line terminator recognized is \n
. (Since
line terminators are included, this also handles \r\n
line endings.)
Line terminators are only included if they are present in the original byte string. For example, the last line in a byte string may not end with a line terminator.
Concatenating all elements yielded by this iterator is guaranteed to yield the original byte string.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = b"\
foo
bar\r
baz
quux";
let lines: Vec<&[u8]> = s.lines_with_terminator().collect();
assert_eq!(lines, vec![
B("foo\n"),
B("\n"),
B("bar\r\n"),
B("baz\n"),
B("\n"),
B("\n"),
B("quux"),
]);
fn trim(&self) -> &[u8] ⓘ
fn trim(&self) -> &[u8] ⓘ
Return a byte string slice with leading and trailing whitespace removed.
Whitespace is defined according to the terms of the White_Space
Unicode property.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B(" foo\tbar\t\u{2003}\n");
assert_eq!(s.trim(), B("foo\tbar"));
fn trim_start(&self) -> &[u8] ⓘ
fn trim_start(&self) -> &[u8] ⓘ
Return a byte string slice with leading whitespace removed.
Whitespace is defined according to the terms of the White_Space
Unicode property.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B(" foo\tbar\t\u{2003}\n");
assert_eq!(s.trim_start(), B("foo\tbar\t\u{2003}\n"));
fn trim_end(&self) -> &[u8] ⓘ
fn trim_end(&self) -> &[u8] ⓘ
Return a byte string slice with trailing whitespace removed.
Whitespace is defined according to the terms of the White_Space
Unicode property.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B(" foo\tbar\t\u{2003}\n");
assert_eq!(s.trim_end(), B(" foo\tbar"));
fn trim_with<F>(&self, trim: F) -> &[u8] ⓘ
fn trim_with<F>(&self, trim: F) -> &[u8] ⓘ
Return a byte string slice with leading and trailing characters satisfying the given predicate removed.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = b"123foo5bar789";
assert_eq!(s.trim_with(|c| c.is_numeric()), B("foo5bar"));
fn trim_start_with<F>(&self, trim: F) -> &[u8] ⓘ
fn trim_start_with<F>(&self, trim: F) -> &[u8] ⓘ
Return a byte string slice with leading characters satisfying the given predicate removed.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = b"123foo5bar789";
assert_eq!(s.trim_start_with(|c| c.is_numeric()), B("foo5bar789"));
fn trim_end_with<F>(&self, trim: F) -> &[u8] ⓘ
fn trim_end_with<F>(&self, trim: F) -> &[u8] ⓘ
Return a byte string slice with trailing characters satisfying the given predicate removed.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = b"123foo5bar789";
assert_eq!(s.trim_end_with(|c| c.is_numeric()), B("123foo5bar"));
fn to_lowercase(&self) -> Vec<u8> ⓘ
fn to_lowercase(&self) -> Vec<u8> ⓘ
Returns a new Vec<u8>
containing the lowercase equivalent of this
byte string.
In this case, lowercase is defined according to the Lowercase
Unicode
property.
If invalid UTF-8 is seen, or if a character has no lowercase variant, then it is written to the given buffer unchanged.
Note that some characters in this byte string may expand into multiple characters when changing the case, so the number of bytes written to the given byte string may not be equivalent to the number of bytes in this byte string.
If you’d like to reuse an allocation for performance reasons, then use
to_lowercase_into
instead.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B("HELLO Β");
assert_eq!("hello β".as_bytes(), s.to_lowercase().as_bytes());
Scripts without case are not changed:
use bstr::{B, ByteSlice};
let s = B("农历新年");
assert_eq!("农历新年".as_bytes(), s.to_lowercase().as_bytes());
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice};
let s = B(b"FOO\xFFBAR\xE2\x98BAZ");
assert_eq!(B(b"foo\xFFbar\xE2\x98baz"), s.to_lowercase().as_bytes());
fn to_lowercase_into(&self, buf: &mut Vec<u8>)
fn to_lowercase_into(&self, buf: &mut Vec<u8>)
Writes the lowercase equivalent of this byte string into the given buffer. The buffer is not cleared before written to.
In this case, lowercase is defined according to the Lowercase
Unicode property.
If invalid UTF-8 is seen, or if a character has no lowercase variant, then it is written to the given buffer unchanged.
Note that some characters in this byte string may expand into multiple characters when changing the case, so the number of bytes written to the given byte string may not be equivalent to the number of bytes in this byte string.
If you don’t need to amortize allocation and instead prefer
convenience, then use to_lowercase
instead.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B("HELLO Β");
let mut buf = vec![];
s.to_lowercase_into(&mut buf);
assert_eq!("hello β".as_bytes(), buf.as_bytes());
Scripts without case are not changed:
use bstr::{B, ByteSlice};
let s = B("农历新年");
let mut buf = vec![];
s.to_lowercase_into(&mut buf);
assert_eq!("农历新年".as_bytes(), buf.as_bytes());
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice};
let s = B(b"FOO\xFFBAR\xE2\x98BAZ");
let mut buf = vec![];
s.to_lowercase_into(&mut buf);
assert_eq!(B(b"foo\xFFbar\xE2\x98baz"), buf.as_bytes());
fn to_ascii_lowercase(&self) -> Vec<u8> ⓘ
fn to_ascii_lowercase(&self) -> Vec<u8> ⓘ
Returns a new Vec<u8>
containing the ASCII lowercase equivalent of
this byte string.
In this case, lowercase is only defined in ASCII letters. Namely, the
letters A-Z
are converted to a-z
. All other bytes remain unchanged.
In particular, the length of the byte string returned is always
equivalent to the length of this byte string.
If you’d like to reuse an allocation for performance reasons, then use
make_ascii_lowercase
to perform
the conversion in place.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B("HELLO Β");
assert_eq!("hello Β".as_bytes(), s.to_ascii_lowercase().as_bytes());
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice};
let s = B(b"FOO\xFFBAR\xE2\x98BAZ");
assert_eq!(s.to_ascii_lowercase(), B(b"foo\xFFbar\xE2\x98baz"));
fn make_ascii_lowercase(&mut self)
fn make_ascii_lowercase(&mut self)
Convert this byte string to its lowercase ASCII equivalent in place.
In this case, lowercase is only defined in ASCII letters. Namely, the
letters A-Z
are converted to a-z
. All other bytes remain unchanged.
If you don’t need to do the conversion in
place and instead prefer convenience, then use
to_ascii_lowercase
instead.
§Examples
Basic usage:
use bstr::ByteSlice;
let mut s = <Vec<u8>>::from("HELLO Β");
s.make_ascii_lowercase();
assert_eq!(s, "hello Β".as_bytes());
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice, ByteVec};
let mut s = <Vec<u8>>::from_slice(b"FOO\xFFBAR\xE2\x98BAZ");
s.make_ascii_lowercase();
assert_eq!(s, B(b"foo\xFFbar\xE2\x98baz"));
fn to_uppercase(&self) -> Vec<u8> ⓘ
fn to_uppercase(&self) -> Vec<u8> ⓘ
Returns a new Vec<u8>
containing the uppercase equivalent of this
byte string.
In this case, uppercase is defined according to the Uppercase
Unicode property.
If invalid UTF-8 is seen, or if a character has no uppercase variant, then it is written to the given buffer unchanged.
Note that some characters in this byte string may expand into multiple characters when changing the case, so the number of bytes written to the given byte string may not be equivalent to the number of bytes in this byte string.
If you’d like to reuse an allocation for performance reasons, then use
to_uppercase_into
instead.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B("hello β");
assert_eq!(s.to_uppercase(), B("HELLO Β"));
Scripts without case are not changed:
use bstr::{B, ByteSlice};
let s = B("农历新年");
assert_eq!(s.to_uppercase(), B("农历新年"));
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice};
let s = B(b"foo\xFFbar\xE2\x98baz");
assert_eq!(s.to_uppercase(), B(b"FOO\xFFBAR\xE2\x98BAZ"));
fn to_uppercase_into(&self, buf: &mut Vec<u8>)
fn to_uppercase_into(&self, buf: &mut Vec<u8>)
Writes the uppercase equivalent of this byte string into the given buffer. The buffer is not cleared before written to.
In this case, uppercase is defined according to the Uppercase
Unicode property.
If invalid UTF-8 is seen, or if a character has no uppercase variant, then it is written to the given buffer unchanged.
Note that some characters in this byte string may expand into multiple characters when changing the case, so the number of bytes written to the given byte string may not be equivalent to the number of bytes in this byte string.
If you don’t need to amortize allocation and instead prefer
convenience, then use to_uppercase
instead.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B("hello β");
let mut buf = vec![];
s.to_uppercase_into(&mut buf);
assert_eq!(buf, B("HELLO Β"));
Scripts without case are not changed:
use bstr::{B, ByteSlice};
let s = B("农历新年");
let mut buf = vec![];
s.to_uppercase_into(&mut buf);
assert_eq!(buf, B("农历新年"));
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice};
let s = B(b"foo\xFFbar\xE2\x98baz");
let mut buf = vec![];
s.to_uppercase_into(&mut buf);
assert_eq!(buf, B(b"FOO\xFFBAR\xE2\x98BAZ"));
fn to_ascii_uppercase(&self) -> Vec<u8> ⓘ
fn to_ascii_uppercase(&self) -> Vec<u8> ⓘ
Returns a new Vec<u8>
containing the ASCII uppercase equivalent of
this byte string.
In this case, uppercase is only defined in ASCII letters. Namely, the
letters a-z
are converted to A-Z
. All other bytes remain unchanged.
In particular, the length of the byte string returned is always
equivalent to the length of this byte string.
If you’d like to reuse an allocation for performance reasons, then use
make_ascii_uppercase
to perform
the conversion in place.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let s = B("hello β");
assert_eq!(s.to_ascii_uppercase(), B("HELLO β"));
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice};
let s = B(b"foo\xFFbar\xE2\x98baz");
assert_eq!(s.to_ascii_uppercase(), B(b"FOO\xFFBAR\xE2\x98BAZ"));
fn make_ascii_uppercase(&mut self)
fn make_ascii_uppercase(&mut self)
Convert this byte string to its uppercase ASCII equivalent in place.
In this case, uppercase is only defined in ASCII letters. Namely, the
letters a-z
are converted to A-Z
. All other bytes remain unchanged.
If you don’t need to do the conversion in
place and instead prefer convenience, then use
to_ascii_uppercase
instead.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
let mut s = <Vec<u8>>::from("hello β");
s.make_ascii_uppercase();
assert_eq!(s, B("HELLO β"));
Invalid UTF-8 remains as is:
use bstr::{B, ByteSlice, ByteVec};
let mut s = <Vec<u8>>::from_slice(b"foo\xFFbar\xE2\x98baz");
s.make_ascii_uppercase();
assert_eq!(s, B(b"FOO\xFFBAR\xE2\x98BAZ"));
fn escape_bytes(&self) -> EscapeBytes<'_>
fn escape_bytes(&self) -> EscapeBytes<'_>
Escapes this byte string into a sequence of char
values.
When the sequence of char
values is concatenated into a string, the
result is always valid UTF-8. Any unprintable or invalid UTF-8 in this
byte string are escaped using using \xNN
notation. Moreover, the
characters \0
, \r
, \n
, \t
and \
are escaped as well.
This is useful when one wants to get a human readable view of the raw bytes that is also valid UTF-8.
The iterator returned implements the Display
trait. So one can do
b"foo\xFFbar".escape_bytes().to_string()
to get a String
with its
bytes escaped.
The dual of this function is ByteVec::unescape_bytes
.
Note that this is similar to, but not equivalent to the Debug
implementation on BStr
and [BString
]. The Debug
implementations
also use the debug representation for all Unicode codepoints. However,
this escaping routine only escapes individual bytes. All Unicode
codepoints above U+007F
are passed through unchanged without any
escaping.
§Examples
use bstr::{B, ByteSlice};
assert_eq!(r"foo\xFFbar", b"foo\xFFbar".escape_bytes().to_string());
assert_eq!(r"foo\nbar", b"foo\nbar".escape_bytes().to_string());
assert_eq!(r"foo\tbar", b"foo\tbar".escape_bytes().to_string());
assert_eq!(r"foo\\bar", b"foo\\bar".escape_bytes().to_string());
assert_eq!(r"foo☃bar", B("foo☃bar").escape_bytes().to_string());
fn reverse_bytes(&mut self)
fn reverse_bytes(&mut self)
Reverse the bytes in this string, in place.
This is not necessarily a well formed operation! For example, if this byte string contains valid UTF-8 that isn’t ASCII, then reversing the string will likely result in invalid UTF-8 and otherwise non-sensical content.
Note that this is equivalent to the generic [u8]::reverse
method.
This method is provided to permit callers to explicitly differentiate
between reversing bytes, codepoints and graphemes.
§Examples
Basic usage:
use bstr::ByteSlice;
let mut s = <Vec<u8>>::from("hello");
s.reverse_bytes();
assert_eq!(s, "olleh".as_bytes());
fn reverse_chars(&mut self)
fn reverse_chars(&mut self)
Reverse the codepoints in this string, in place.
If this byte string is valid UTF-8, then its reversal by codepoint is also guaranteed to be valid UTF-8.
This operation is equivalent to the following, but without allocating:
use bstr::ByteSlice;
let mut s = <Vec<u8>>::from("foo☃bar");
let mut chars: Vec<char> = s.chars().collect();
chars.reverse();
let reversed: String = chars.into_iter().collect();
assert_eq!(reversed, "rab☃oof");
Note that this is not necessarily a well formed operation. For example,
if this byte string contains grapheme clusters with more than one
codepoint, then those grapheme clusters will not necessarily be
preserved. If you’d like to preserve grapheme clusters, then use
reverse_graphemes
instead.
§Examples
Basic usage:
use bstr::ByteSlice;
let mut s = <Vec<u8>>::from("foo☃bar");
s.reverse_chars();
assert_eq!(s, "rab☃oof".as_bytes());
This example shows that not all reversals lead to a well formed string. For example, in this case, combining marks are used to put accents over some letters, and those accent marks must appear after the codepoints they modify.
use bstr::{B, ByteSlice};
let mut s = <Vec<u8>>::from("résumé");
s.reverse_chars();
assert_eq!(s, B(b"\xCC\x81emus\xCC\x81er"));
A word of warning: the above example relies on the fact that
résumé
is in decomposed normal form, which means there are separate
codepoints for the accents above e
. If it is instead in composed
normal form, then the example works:
use bstr::{B, ByteSlice};
let mut s = <Vec<u8>>::from("résumé");
s.reverse_chars();
assert_eq!(s, B("émusér"));
The point here is to be cautious and not assume that just because
reverse_chars
works in one case, that it therefore works in all
cases.
fn reverse_graphemes(&mut self)
fn reverse_graphemes(&mut self)
Reverse the graphemes in this string, in place.
If this byte string is valid UTF-8, then its reversal by grapheme is also guaranteed to be valid UTF-8.
This operation is equivalent to the following, but without allocating:
use bstr::ByteSlice;
let mut s = <Vec<u8>>::from("foo☃bar");
let mut graphemes: Vec<&str> = s.graphemes().collect();
graphemes.reverse();
let reversed = graphemes.concat();
assert_eq!(reversed, "rab☃oof");
§Examples
Basic usage:
use bstr::ByteSlice;
let mut s = <Vec<u8>>::from("foo☃bar");
s.reverse_graphemes();
assert_eq!(s, "rab☃oof".as_bytes());
This example shows how this correctly handles grapheme clusters,
unlike reverse_chars
.
use bstr::ByteSlice;
let mut s = <Vec<u8>>::from("résumé");
s.reverse_graphemes();
assert_eq!(s, "émusér".as_bytes());
fn is_ascii(&self) -> bool
fn is_ascii(&self) -> bool
Returns true if and only if every byte in this byte string is ASCII.
ASCII is an encoding that defines 128 codepoints. A byte corresponds to
an ASCII codepoint if and only if it is in the inclusive range
[0, 127]
.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
assert!(B("abc").is_ascii());
assert!(!B("☃βツ").is_ascii());
assert!(!B(b"\xFF").is_ascii());
fn is_utf8(&self) -> bool
fn is_utf8(&self) -> bool
Returns true if and only if the entire byte string is valid UTF-8.
If you need location information about where a byte string’s first
invalid UTF-8 byte is, then use the to_str
method.
§Examples
Basic usage:
use bstr::{B, ByteSlice};
assert!(B("abc").is_utf8());
assert!(B("☃βツ").is_utf8());
// invalid bytes
assert!(!B(b"abc\xFF").is_utf8());
// surrogate encoding
assert!(!B(b"\xED\xA0\x80").is_utf8());
// incomplete sequence
assert!(!B(b"\xF0\x9D\x9Ca").is_utf8());
// overlong sequence
assert!(!B(b"\xF0\x82\x82\xAC").is_utf8());
fn last_byte(&self) -> Option<u8>
fn last_byte(&self) -> Option<u8>
Returns the last byte in this byte string, if it’s non-empty. If this
byte string is empty, this returns None
.
Note that this is like the generic [u8]::last
, except this returns
the byte by value instead of a reference to the byte.
§Examples
Basic usage:
use bstr::ByteSlice;
assert_eq!(Some(b'z'), b"baz".last_byte());
assert_eq!(None, b"".last_byte());
fn find_non_ascii_byte(&self) -> Option<usize>
fn find_non_ascii_byte(&self) -> Option<usize>
Returns the index of the first non-ASCII byte in this byte string (if
any such indices exist). Specifically, it returns the index of the
first byte with a value greater than or equal to 0x80
.
§Examples
Basic usage:
use bstr::{ByteSlice, B};
assert_eq!(Some(3), b"abc\xff".find_non_ascii_byte());
assert_eq!(None, b"abcde".find_non_ascii_byte());
assert_eq!(Some(0), B("😀").find_non_ascii_byte());
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.